2 The owa_cache Package

The owa_cache package contains functions and procedures that enable the PL/SQL Gateway cache feature to improve the performance of your PL/SQL web application. This section describes the specification of these functions and procedures.

2.1 Summary

owa_cache.disable - disables the cache for this particular request.

owa_cache.set_expires - sets up the cache headers for expires model cache type.

owa_cache.set_cache - sets up the cache headers for validation model cache type.

owa_cache.set_not_modified - sets up the headers for a not modified cache hit (used in the Validation technique model only).

owa_cache.get_level - returns the caching level (used in the Validation technique model only).

owa_cache.get_etag - returns the tag associated with the cached content (used in the Validation technique model only).

2.2 owa_cache.disable

This disables the cache for this particular request.

Table 2-1 owa_cache.disable

Properties	Definitions
Parameters:	None
Exceptions:	None

2.3 owa_cache.set_expires

This sets up the cache headers for expires model cache type.

Table 2-2 owa_cache.set_expires

Properties	Definitions
Parameters:	p_expires IN - the number of minutes this content is valid. p_level IN - the caching level for it.
Exceptions:	VALUE_ERROR is thrown if p_expires is negative or zero, or p_level is not 'USER' or 'SYSTEM', or p_expires is > 525600 (1 year).

2.4 owa_cache.set_cache

This sets up the cache headers for validation model cache type.

Table 2-3 owa_cache.set_cache

Properties	Definitions
Parameters:	p_etag IN - the tag associated with this content. p_level IN - the caching level for it.
Exceptions:	VALUE_ERROR is thrown if p_etag is greater than 55, or p_level is not 'USER' or 'SYSTEM'.

2.5 owa_cache.set_not_modified

This sets up the headers for a not modified cache hit. It is used in the Validation technique only.

Table 2-4 owa_cache.set_not_modified

Properties	Definitions
Exceptions:	VALUE_ERROR is thrown if ETag was not passed in.

2.6 owa_cache.get_level

This returns the caching level. It is used in the Validation technique model only.

Table 2-5 owa_cache.get_level

Properties	Definitions
Returns:	The caching level string ('USER' or 'SYSTEM') for cache hit; null otherwise.

2.7 owa_cache.get_etag

This returns the tag associated with the cached content. It is used in the Validation technique only.

Table 2-6 owa_cache.get_etag

Properties	Definitions
Returns:	The tag for cache hit; null otherwise.